C-peptide (Serum/Plasma) with High-Performance Liquid Chromatography (HPLC) Measurement

Why Is This Test Done?

Your healthcare provider may order a C-peptide test to diagnose or monitor conditions like type 1 or type 2 diabetes, especially when insulin levels alone may not be sufficient. It can also help distinguish between insulin-dependent and insulin-independent causes of low blood sugar. Additionally, it may be used to evaluate pancreatic function in people with unexplained weight loss, nausea, or other symptoms of diabetes.

What Does the Test Measure?

C-peptide is released into the bloodstream along with insulin during digestion. Unlike insulin, C-peptide is not stored in the body, so its levels reflect real-time insulin production. Measured via HPLC, this test provides precise quantification of C-peptide mass concentration in your serum or plasma sample.

How Is the Test Performed?

A blood sample is drawn from a vein, typically in your arm. The sample is then processed and analyzed using high-performance liquid chromatography (HPLC), a method that separates and measures C-peptide molecules based on their chemical properties.

What Are Common Uses?

C-peptide testing is particularly useful in diagnosing diabetes when insulin levels are unclear. It can also help determine if insulin therapy is working effectively or if there’s a problem with insulin production. Some doctors use it to check for conditions like pancreatic cancer or other pancreatic disorders that may affect insulin secretion.